Box motion for looms



Aug. 7, 192&

w. E. LUNDGREN BOX IOTION FOR LOOKS Filed Nov. 15. 1926 2 Sheets-Sheet 1 [in enfor W/V/fd/ii E LM /P/I Aug. 7, 192&

W. E. LUNDGREN BOX IOTION FOR LOOKS Filed Nov. 15, 1926 2 Sheets-Sheet 2 Patented Aug. 7, 1928.

UNITED STATES v 1,679,616 PATENT OFFICE.

WILLIAIM E. LUNDGREN, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO CROMPTON 8cKNOVVLES LOOM WORKS, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

BOX MOTION For. LOOMS.

Application filed November 15, 1926. Serial No. 148,427.

. two positioning mechanisms which may be actuated either singly or in unison.

It has been customary to provide a counterweight for the drop boxes which would offset to a greater or less extent the quite considerable weight of the boxes and the supports therefor. Such counterweights, as previously provided, have been defective and unsatisfactory in operation, as they have not equalized the strain upon the different parts of the operating mechanism and furthermore their construction has rendered them expensive and subject to wear and deterioration.

It is the general object of my invention to provide an improved construction and I disposition of counterweightfor a mechanism of the class described, so constructed and I positioned that it will substantially equalize the strains upon the two separate operating mechanisms for, the drop box lifting lever while at thesame time it largely counter-balances the weight of the drop boxes and their'supporting mechanism.

A further object is to so design and apply a counterweight that it Willnot only take care of the static forces but that it will also substantially equalize the stresses due to the angular motion of the connectors and to the inertia of the moving parts.

A preferred form of the invention is shown in the drawings, in which Fig. 1 is a side elevation of my improved mechanism;

Fig. 2 is a plan view, taken along the line 2-2 in Fig. 1, and

Figs; 3,4 and 5 are side elevations of certain. parts showing successive operating positions thereof. v

Referring to the drawings, I have shown portions of a drop box loom which is in gencial of the usual construction and which comprises a frame having a lay 11 and drop'boxes 12, mounted to swing about a rock shaft 13 and actuated by connecting rods 14 from a crankshaft 15 in the usual manner. upon a lifter rod 16 guided for vertical movement in a lower bearing or bracket 17 The drop boxes 12 are mounted' and connected with a drop box lifting lever 20, by a give-way link or connection 21.

The lever 20 is mounted on a stud 22 secured in an arm 23 supported upon a fixed pivot 24. 23 is connected by a link 25 (Fig. 3) to a crankpin 26 mounted in a disc 27 secured. to one end of a pinion shaft 28 (Fig. 1). A pinion 29 is keyed on the shaft 28 and is slidable into and out of position for engagement by the segmental gear teeth of a mutilated gear 30. I

A second link 32 (Fig. 3) is pivoted at 33 to a rear portion of the drop box lever 20 and is connected at its lower endto a crankpin 34 on a disc 35 fixed on a pinion shaft 36 having a second sliding pinion 37 keyed thereon and also adapted for engagement by the segmental teeth of. the mutilated driving gear 30. I The pinions 29 and 37 are moved axially into and out of engaging positions by clutch levers 38 and 39 controlled through rods 40 and 41 from the usual drop box pattern mechanism (not shown). This actuating mechanism for selectively rotating the pinion shafts 28 and 36'and the crankpins 26 and, 34 is all of the usual commercial construction and in itself forms no part of my present invention.

It has been customary heretofore to attach a counterweight to the lever 20 at a point forward of the stud or pivot 22. The counterweight has been of large size and has been connected with the lever 20 byv found to exert very uneven pressures upon the teeth of the driving pinions 29 and 37.

It has been determined, for instance, that the usual twenty-pound counterweight, ap plied as above described, caused a load of about twenty-seven pounds to be exerted upon the teeth of the back pinion 37, while the corresponding load upon the teeth of the front pinion 29 was less than eight pounds. y

In my improved construction, I mount a small counterweight 42 directly upon the The outer end of the arm rear end of the drop box lifting lever 20. The weight 42 may be cast integrally with the lever 20, but it is sometimes desirable to provide for slight adjustment of the weight and for this purpose I prefer to mount the weight 42 slidaloly upon the lever 20, securing it in desired position. by a set screw l3 or other equivalent fastening mechanism.

The advantages derived from placing the counterweight 42 directly upon the rear portion of the lever 20, instead of attaching a much heavier counterweight forward of the pivot 22, are much greater than would be expected from a casual inspection of the apparatus.

It is found, for instance, that a six-pound counterweight will produce as much counterbalancing effect as was produced by the previous twenty-pound counterweight applied forward of the pivot 22. Furthermore,it is found that the counterweight l2, if properly designed and. located, will sub-- stantially equalize the pressures upon the front and rear driving pinions. For instance, a six-pound counterweight mounted at an effective leverage of about twelve and a half inches rearward from the pivot will exert a pressure of substantially sixteen and one-half pounds upon *both the front and the back driving pinions. The forces acting on the pinions are thus sub stantially equalized and the wear on different portions of the drop box operating mechanism is made substantially uniform.

The substitution of my improved construction not only equalizes the wear upon the drop box actuating mechanism, but also substantially redu the cost of manufacture, due to the decreased size of the weight and the direct application thereof and it also en tircly eliminates wear or deterioration in the counterbalancing mechanism and provides additional and greatly desired clearance for other portions of the drop box mechanism.

It has been found also that the design and locaion of the counterweight as set forth in this application rcouces the total power required for lifting the drop boxes to their various positions and also very substantially 1()(lHC(-?S the maximum amount of power required at any one ")oint for producing such movements.

It should be noted that the design and ap-- plication of a satisfactory counterweight is greatly complicated by the compound leverage of the parts and by the fact that the terweighting has been in force for very many years and it was not even suspected that the counterbalancing could be improved until applicants construction was applied and actual tests and demonstrations showed the great advantages to be attained by the use thereof.

Having this described my invention. and the advantages thereof, 1 do not wish to be limited to the details herein shown and described otherwise than as set forth in the claims, but what I do claim is 1. in a drop box loom, a plurality of drop boxes, a lifting lever therefor, a floating pivot for said lever, an arm on which said pivot is mounted, raid arm swinging upon a pivot fixed in position substantially forward of said floating pivot and said arm also extending substantially rearward of said floatin pivot, actuating meansengaging the rear end of said arm to move said floating pivot. additional actuating means positioned rearward of said first actuating means and eng ging said lifting leved and effective to s ving said lever on its floating pivot, and a counterweight for said drop boxes mounted directly on said lifting lever at a point rearward of the connection of said second actuating means thereto.

2. drop box loom, a plurality of drop box e, a. lifting lever therefor, a floating pivot for said lever, an arm on which said pivot is mounted, said arm swinging upon a pivot fixed in position substantially forward of said floating pivot and said arm also extending substantially rearward of said floating pivot, actuating means engaging the rear end of said arm to move said floating pivot, additional actuating means positioned rearward of said first actuating means and engaging said lifting lever and effective to swing said lever on its floating pivot, and a relatively light counterweight for said drop boxes applied directly to the rear end of said lifting lever and in a position effective to substantially equalize the forces to be overcome by said first and second actuating means at their points of application to said arm and to said lifting lever respectively.

in testimony whereof I have hereunto a'llived my signature. V

WILLIAM E LUNDGREN. 

